The present invention relates to a tension clamp for a cable supporting an insulated electrical conductor or for an insulated electrical cable.
French Patent 86 16027 teaches a tension clamp for an insulated electrical conductor equipped with a supporting cable, likewise insulated.
This clamp includes a sheath slit lengthwise, provided with an anchoring element and a tapered cavity inclined at a slight angle in which a compressible core is slidably mounted. The core has on each side a lengthwise cavity able to be enlarged laterally to accommodate an electrical conductor or its supporting cable and to be compressed at the same time as the core, around the electrical conductor or its supporting cable when the latter is displaced lengthwise toward the apex of the tapered cavity in the sheath, up to the point where it is blocked, thus locking the electrical conductor or its supporting cable by wedging action.
In this clamp, the compressible core includes two prismatic jaws forming wedges that are connected axially, but are capable of limited transverse movement, toward or away from each other.
This clamp, which gives complete satisfaction in application, suffers from the drawback of having two jaws forming wedges, which increases its selling price due to the cost of its manufacture and its installation, which is complex because of the need to connect the two jaws axially. Attempts have been made to eliminate one of the jaws by giving the part of it serving as a bearing in the cavity of the sheath, the shape of a cylindrical section serving as a cradle for the cable. Attempts made in this direction have proved fruitless since when the cable was energized, it and the single jaw slid in the sheath and the friction generated by the sliding of the cable in its cradle both braked this sliding, which impaired the grip of the cable, and strongly threatened to alter or even totally destroy the cable insulation. Moreover, forces generated by the wedging action of the cable between the single jaw and its cradle located in the sheath cavity have the effect of expelling the jaw.